Most athletic shoes used for field sports, such as soccer, football, baseball, softball and lacrosse, have a number of either tapered or blade-like cleats for the purpose of increasing traction. Cleats dig into the turf to prevent slipping during starting, stopping, and cutting maneuvers.
Such cleats, however, in addition to providing desirable traction for starting, stopping and cutting, typically provide very undesirable resistance to pivoting. This can be a disadvantage in two ways.
When pivoting is inhibited, the maneuverability of the athlete is limited. His performance is less than it could be. Enhancing the ability of a player to pivot can greatly increase his effectiveness on the field.
In addition to inhibiting certain pivoting actions which athletes attempt or would like to attempt, many cleats of the prior art tend to resist turning movements which can relieve stresses within the leg when unwanted torque or force is applied to the athlete, particularly to the athlete's leg. If a twisting moment is forcibly applied to a leg at a time when the cleats are firmly planted into the turf and release from the turf is not possible, injuries can result, particularly common knee injuries.
Some athletic shoes have cleats intended to accommodate pivoting movements. One approach has used fixed annular cleats. The performance of such shoes can vary greatly, depending on various factors However, the annular-cleated athletic shoes of the aforementioned U.S. patents provide greatly improved pivotability and excellent traction, and reduce the chance of athletic injuries.
The improvement in pivotability made possible with shoes in accordance with the principles of such patents is dramatic, and such shoes give the athletes wearing them a natural feeling of freedom together with a good feeling of traction for stopping, starting and cutting.
The invention described and claimed herein relates generally to athletic shoes having substantially continuous annular cleats. The substantially continuous annular cleats are modified to provide particular advantages In some cases, modifications in the annular cleat can significantly improve the performance of such shoes.
While good pivotability is highly desirable, in certain cases it is desirable to control the degree of pivotability, but to do so without eliminating or substantially reducing the ability of the shoe to pivot while firmly planted. That is, without losing the pivotability characteristic which serves to avoid knee injuries and other leg injuries, having a measure of control in pivoting would be desirable.
Because of their structural characteristics, annular cleats can tend to reduce sole flexibility to come extent But having a high degree of sole flexibility is desirable because it gives the shoes a natural feeling, allowing the normal bending of the sole of the foot to be expressed through the sole of the shoe.
A high degree of sole flexibility is considered of particular importance in certain field sports, such as soccer, where complete control of foot movements is advantageous. The fine foot movements which are used in soccer for ball control are particular examples. Thus, having means to improve sole flexibility without sacrificing the advantages of pivotability would be desirable.
It is also believed that sole inflexibility can tend to be a negative factor with respect to sole wear characteristics, causing undue pressures at certain points in the sole. Having means to improve the degree of sole flexibility could be desirable in this respect, improving sole durability.
Another concern with cleated sports shoes is the accumulation of mud in the cleats. While mud accumulation is not as significant a problem for the annular-cleated shoes of the aforementioned patents as it is for standard cleated athletic shoes, mud accumulation remains a concern, particularly for players of light weight. Increased sole flexibility can tend to further improve the mud-shedding qualities of such shoes. For this and other reasons, increased sole flexibility is especially important for lightweight athletes.
Good penetration of the ground is essential to obtaining excellent traction in cleated athletic shoes. There remains a need for still further improvement in shoe traction and hence in shoe penetration, in order to achieve higher levels of athletic performance. Good penetration ability is particularly important to lightweight athletes, since penetration is aided by greater weight. This is particularly so if mud is present in the cleats in position to block or retard ground penetration.
Good ground penetration is also helpful for obtaining good pivotability in the annular cleated shoes. Insufficient penetration will result in less ground bearing than is needed for the best possible improved pivotability.
Ground penetration will be affected by, among other things. the total cleat end area--that is, the total area of the distal surface(s) of the cleat or cleats. In general, the greater the total end area bearing on the ground, the more difficult it may be for an annular cleat to penetrate the ground; the smaller the total end area bearing on the ground, the easier is may be for an annular cleat to penetrate the ground. This affect is accentuated when the ground is hard.
Sharpening the distal end of the annular cleat reduces the total area of the distal surface and tends to enhance penetration, but may also cause some concern about possible injury from player contact with such sharp edges. With of these conflicting concerns, there is a need for an improved athletic shoe sole with cleating providing good ground penetration to insure the aforementioned excellent combination of traction and pivotability in a comfortable functional athletic shoe.
Good traction in various athletic movements on the playing field is of great importance. In particular, quick stopping ability is very important. Good ability to stop quickly from forward movement is helpful in many sports; good ability to stop quickly from rearward (backpedaling) movement is helpful as well. particularly for certain players such as those in defensive positions in soccer and football. There is a need for an improved athletic shoe with enhanced stopping ability.
In many cases, an athlete in a quick backing/stopping/advancing sequence of motions finds it necessary to turn his feet sideways, at least to some extent, on reversing from the backward to the forward direction. Turning the feet sideways can take time at a time when split seconds may be important.
There is a need for an improved athletic shoe sole providing an athlete good traction in such maneuvers without the need to turn his feet sideways. And, there is a need for a sole giving improved traction on starting and accelerating.
It has been found that in some forms athletic shoes in accordance with the aforementioned U.S. Pat. No. 4,577,422 may make a snapping or clapping sound during running on wet ground--particularly when an athlete is running backwards. Opinions may differ on whether this is a negative, neutral or even a positive trait. On balance, however, eliminating or reducing such noise would be desirable.
Before describing the invention, a brief description of the foot and its pivoting and planted positions will be helpful. This can serve as an aid in understanding preferred embodiments of this invention.
The sole of the foot includes four basic portions. These are, in order back to front: the heel portion; the arch portion; the ball-of-the-foot portion; and the toe portion. The heel portion and the ball-of-the foot portion are those portions which share most if not all of the player's weight when the player is in a normal standing position with his feet generally flat on the ground. In such position, the arch portion and toe portion bear little if an weight.
When a player is "on his toes" in a "ready" position, virtually all of the player's weight is normally shared by the toe portion and the ball-of-the-foot portion. The same is usually true when a player is "digging" in a running action. Indeed, when a player is in the ready position the juncture of the phalanges (toe bones) and the metatarsals is the center of weight bearing. In other words, the center of weight bearing in the forward portions of the foot actually moves forward when a player shifts to the ready position.
The sole of an athletic shoe has portions immediately below such four foot portions which may be designated, and herein are designated, by the same terms.